The present invention relates to pop-up display structures, and more particularly to a hub mechanism and a hinge mechanism for a channel bar.
Pop-up display structures are prevalent in the trade show industry and generally comprise lightweight tubular structures that are capable of being transported, set up, and repacked in a relatively short time frame. The display structures include skeletons that typically comprise a set of pivotally attached tubes that are held together by hubs and that are capable of folding compactly for storage and shipping in containers, such as plastic storage cases. When the structure is moving into its expanded state, the tubes are allowed to rotate and expand about the hubs. The individual tubes are pivotally attached to the hubs, such that they can rotate from the folded to the expanded position. Once the display structure is expanded into position, the tubes are typically locked into position so that the structure cannot collapse.
After the skeleton is in place, a set of channel bars are attached to cover each row of hubs. The channel bars give the final structure a smooth and seamless appearance. After the channel bars are all attached to cover the hubs, a set of display panels is attached to the frame by magnets or other fasteners, such as hook and loop fasteners and the like.
Most of the existing systems require the tube frames to be fastened to the hub by means of rivets, screws, or push pins. These systems require tools in order to disassemble the apparatus to replace tubes or to repair or reconfigure the structure.
The channel bars are typically hinged into multiple sections due to their length so that they can be folded for storage and transport. Existing systems use unhinged parts or bungee cords or a variation of a butt hinge.
What is needed is a hub and hinge mechanism for a pop-up display structure that is easy to use, easy to manufacture, and that can be adjusted in the field without tools.
The present invention meets the above-described need by providing a hub mechanism that divides into two sections by means of a thumb screw. The two sections have channels defined therein that form a seat for a set of guide pins attached to the end of the tubes. The guide pins are captured in the seat formed by the channels in the two sections, and the guide pins pivot about the point defined by the seat inside the hub. The hub has a slot next to the seat that allows the tubes to rotate about the hub between the collapsed and expanded positions for the display structure. By means of the thumbscrew the two sections of the hub can be divided. Once the sections are divided by a certain distance, the guide pins that are attached to the end of the tubes are capable of slipping out of the hub such that the tubes can be removed for reconfiguration of the structure or for repair. Accordingly, the tubes can be removed without requiring the use of any tools.
The thumbscrew also provides a seating structure for the channel bars. Once the display structure is locked in its deployed condition, the channel bars are attached to the outside of the frame. The channel bars attach by means of a slot that slidingly engages with the head of the thumbwheel. The channel bars of the present invention are divided into three sections so that they can be folded compactly for storage and transportation. The sections are hingedly attached to one another such that they can be folded up without regard to the sequence of the folds. A sliding cam link connects adjacent sections of the channel bar. Each end of the link is pivotally attached to the contiguous sections. One end of the link is attached to and pivots about a pin that is spring biased and that travels in a slot. If another section has previously been folded over the midsection, the link is capable of moving forward against the force of the spring to increase the pivoting radius of the link and therefore to increase the clearance for folding the contiguous section over a previously folded section. If there is not a previously folded section, the cam link does not move along the slot as much and the contiguous section is capable of folding directly over the midsection and abutting the midsection along its entire length.
Accordingly, the present invention offers several advantages including providing for reconfiguration or replacement of tubes in a pop-up display structure without tools.
Another advantage is that the present invention provides for simplified mounting of the channel bars directly to the thumbwheel.
Also, the present invention provides for folding of the channel bars without regard to sequence.